Apparatus for absorbing solar energy



J R. H. GODDARD APPARATUS FOR ABSORBINGV SOLAR ENERGY.

Aug. 14, 1934,

Filed Oct. 50. 1930 l nw wimax, IM D. Mfkwf/ Patented Aug. 14, 1934 *UNITED PATENT] OFFICE i 1,969,839) Y APPARATUS FOR ABSORBING SOLAR -ENERGY Robert H. Goddard, Worcesten Mass. Application October-'30, 1930,*-Serial No. 492,267

" 1v-claims, (01.-,126-271) This invention relates tol apparatus bywhich solar energy may be effectively utilizedin the heating of water, the .production of steam orthe raising of any fluid to a higherl temperature.

It is the generalobject of my invention Ato pro. vde apparatus for such purposes so designed that a relatively large heating action maybe attained by use of a relatively small apparatus.' l

A further object of my invention is to provide apparatus which issimple in construction,f,re liable and ecient in operation and 'vs'fhiclilin-V volves the use of no moving parts.

My improved apparatus produces'frapid and complete vaporization of a liquid at high temperatures, withV a minimumfloss of heat during the vaporizing operation. 1' Y My invention further relatesto arrangements and combinations of parts which `willbe hereinafter described and more particularly pointed out in? the appended claims.

A vpreferred form of the invention is shown in the drawing, in which Fig'. 1 isa longitudinal sectionalview of my improved apparatus; Fig. 2 is a partial sectional view, taken along theline 2-2'inFig.1;' f Fig. 3 is an end View of .a detail part, vlooking in the direction of the'arrown in Fig.,2;`

Fig. 4 is a sectional elevation, taken along the lin'e 4-4 in Fig. 1; and f' Fig.` 5 is Va fragmentary sectional view of V a modiedstructure. Referring to i:he'drawing, my-improvedheating apparatus comprises afrelativelylong and preferably conical tube 10, suitably supported in a casing 11 of insulating 4material.` Thellength of the tube 10 should be fsubstantiallygre'ater than twice' its longest diameter. A substantially Lhemisphe'rical window 12A of'qu'artz or lvery transparenty glass is mounted'at the large end ofV the fconical tube 10 and is held inposition by clamping rings 14 and bolts 15. Whentheapparatus is exposed to strong winds, a second and outer similar window 16 is Ipreferably mounted in spaced relationto the window 12. .A4 refractory `disc 18 may besecured to Athe front of .the ,apparatus, protecting the edge portionsof the windows from excessive heat. v :.1

The conical tubelO is Vconnected at itszrearend through a'passage 20.to a mixing-and drying chamber -22 which ispreferablyxof :substantially cylindrical fform. A barrier 23w at therear kend of the passage restrictstheoutlet ofthe pas circulatingspace v and are concentrated at `a `r'r'ie` mber 32 may be.` ofv` hollow metal yconstructo flow'in asubstantially tangential direction asit enters the chamber 22.

A discharge passage 24 projects in Ythrough theside ofthe chamber which is opposite to the passage 20 Aand provides for the discharge of 60 highly heated vaporY from Ythe mixing and drying chamber.

K The projecting innerrend of the discharge passage is preferably coated or built up to a sub- 'stantially streamlike section, as indicated at 25 65.

i n`Fig `3, thus reducing the interference with the rapidA circulation of the liquid and vapor within the mixing chamber.

' Fine mesh metal screens 27 are preferably provided inthe eharnber 22 to effect the breaking 70 up .an'd'complete vaporization of any liquid en?. trained in the vaporrentering the mixing chamb'er. Similar screens`28 may be Vprovided in the passage 20 f or'asirnilar purpose.

'The discharge passage 24. is preferably in the form of an outwardly enlarged conical nozzle through which the highly heated vapors are discharged for :heating or other desired purposes.

. The conical tube 10 is preferably formed of relatively thin metal and is highly polishedon its inner surface. The window 12 encloses a sub#- stantial fluid-circulating space 30 in front of the large end of the conical tube 10.

Assuming that this space and the interior of the tube-.10 have been supplied with water or other iiuid in a manner to be described,.the action of this Vpart of the apparatus, when exposed to the heat of Vthe. sun,v is as follows:-

Ultra violet or heat rays R traverse the Viiuid point Yinsidern thelarge end of the conical tube ,l( .wi1hese` heatrays rtraverse the liquid i'nfythe tube l0V and are repeatedly reflected back and V forth by the polished internal cni'cal'surfa'ce'of the'ftube. whch, however, of suchslight 'in- 95V Vclination thatthe rays are not to any substantial extent reflected. back into' the space 30.

The heat nof vthe rays Ris thus rapidly absorbed by the.liquid in the space 30 and tube 10, raising the temperature thereof and causing vapor to be formed, which va'por is discharged rearward through thepassage 2 0 to thernixing chamber 22 in'which the vaporization'iscompleted, the dry "vapor lbeing discharged through lthe nozzle 24;"

. 1 1o V"Ih'e'action within the tube 10 may be faciliv5 in,"saidrnember 32 being centrally located in the Ytube 10 by guy wires 3 3, (Figs. 1 and 4)'. The

les

provided with spirally arranged partitions` 922- Which cause the entering liquid to traverse a helical path and to repeatedly encircle the nozzle' 24, the chamber 22 and the vconnectingVV passage 20.

'I'he liquid then enters a space or passage 5 0 which surrounds the conical tube 10 but isspaced therefrom by a portion of insulating materiall which is of increased thickness toward the small end of the tube Where the temperatures-larev higher.. y Thepassage -is 'alsol'providedj with spiral partitions 53 forming a second helical path through which the liquidlis conducted' to the front e'nd of thel tube 10; where it is discharged in a tangential direction through openings 54 into ythe'circulating kspace '30"` previously Vdescribed. 'y The outside of the apparatusis preferablyprovided witlra metal 'casing 60,fimpervious to air and particularly` designed to protect the more or less porous insulating material from the action of wind. v

Experiments with the apparatus indicate that its high efficiency is due in part to the fact that 35A Vaporization of the liquid 'takes place through- 'out thel entire body of the liquid in the conical tube'l() and is not coniined to those p'crtionsof liquid in Contact With'the tube itself, which, `due to its reflecting surfacadoes not absorb an appreciable vamount .o f'heat. i

The liquid traversing the passages 41'VV and'50 enclosing the inner heating portions fof r`the apparatus serves to absorb: such heat asmay escape through the insulating material of the walls, but vit is still at relatively low temperature when Iit enters the circulating space 30 and thus' serves to prevent the Window 12 from becoming overvheated. Y

It will also be noted'that as the liquid enters theA conical tube 10, the cooler portions of the liquid tend to moveto the outside of the cone in contact with the reflecting metal, so that heat losses through'the tube 10 are reduced and the ytemperature of the tube 10 ordi.n aril'y remains `below that ofthe liquid and vaporlilowing therethrough;l The' provision of the inner conical lmember 32 makes the action Oftheapparatus more denitei and rapid. n Y A Itjmay be noted Vthat the ultra-violet rays transmitted by the window 1 2 wh`en quartz' is used are highly concentrated` in thetube 10 and have va strong st erilizingaction which is' of great lirnportance under certain circumstances'.V n

In cases wherek it is Lnot essential that the liquidbe completely vaporiaed, as where the liquid is `to bel used for, heating only, the, mixing chamber and -nozzle may jbeA dispensed with,V as

shown in Fig. 5, in which case theliqud enters directlythrough .a pipe to a helical passage surroundingthe conical tube 10. In this conystructionmthe vaporformed the tube, `10 may lbe discharged the details herein disclosed, otherwise than as set forth in the claims, but what I claim is:-

1. Apparatus for absorbing solar energy comprising a conical tube having an internal reflecting surface, a transparent window through which solar heat rays are admitted to the larger end of said tube, a conduit through which a heat-absorbing fluid is vdelivered to said tubethrough its larger open end, and means to conduct `heated fluid from the smaller end of said tube, said transparent window being substantially semispherical and inclosing a fluid-circulating space Yof, substantial volume in front of said conical tube.

2, Heat-absorbing apparatus as set forth in claim 1, Ain-'tvhich the conduit opens directly and freely into said Huid-circulating space.

3. Heat-absorbing apparatus as set forth in claim- 1, in which the conduit is mounted and connected to deliver the heat-absorbing fluid directly into said fluid-circulatingspace in a tangential direction. j

A1i. Apparatus for absorbing solar 'energycomprising a conical tubehaving an internalr'eecting surface, a transparent window through which solar heat 'rays are admitted to the vlarger l end of vsaid tube, a conduit through which aheat'- absorbing iiuid is deliveredto said tubethrough its largerv openend, and meansto conduct heated fluid from' ,the smaller end of said tube, said transparent window consisting of two concentric semi-spherical portions mounted in spaced relation to eachother.

5 Apparatus for `absorbing' solar energycornprising a conical tube having an kinternal'reflecting surface, a transparent window through which solar heat. rays are admitted to the larger end of said' .'tub`e,"a' conduit through which a` heat-absorbing fluid is delivered to saidA tube through its larger open end, andfmeans to 'conduct'heated iiuid from the smaller end of said4 tube, said meansvforconducting away'heated Vfluid including a mixing andv drying chamber. f

6. Heat-absorbing apparatus as set forth in claim 5, in which an outwardly-enlarged conical discharge nozzle is included; having its inner end opento said chamber vand saidjnozzlev extending outwardly-therefrom. l *2" g' '7.He'at-absorbi`ng apparatus as `set forth in claim 5l in which an outwardly-enlarged'conical discharge nozzle' isincluded,l said nozzle Vhaving its inner end projecting into saidmixing and drying chamber and said inner end havingastreamline external'surface.

8, Heatabsorbing 'apparatusassetlforth' in ing-up and more 'complete vaporization of liquid entrain'ed in 'the `heatedvapor which enters said chamber. V U j- 9.- Heat-absorbing apparatus as set` forthv -in claim 5,'-in which'the mixing and drying chamber is of substantially cylindricalcross section and is providedWithagdischarge outlet and with an inlet connection from said conical tube,'sai'd inlet connectionv being `so disposed thxtt'fvapor` enters said chamber from said connection ina'substantially tangentialdirection. A 'L 1 Tl i I 1 Y n.10; Apparatus for absorbing solarenergy comprising aconical'tube having an internalreect- 'ing isurfacafza 'transparent windowA through `which Solar heat raysrare admitted to the .largerlend4 of said tube, a conduit through which aheat-"absorbing fluid isfielivered'y .tdsaid tube',through-y its larger open end, and means to conduct heated fluid from the smaller end of said tube, said means for conducting away heated fluid including a mixing and drying chamber and a discharge nozzle, a thick heat-insulating covering for the external surfaces of said apparatus, and an outer casing for said apparatus and insulating covering, which is substantially impervious to air.

11. Apparatus for absorbing solar energy comprising a conical tube having an internal reflecting surface, a transparent window through which solar heat rays are admitted to the larger end of said tube, a conduit through which a heat-absorbing uid is delivered to said tube through its larger open end, means to conduct heatedfluid from the smaller end of said tube, said means for conducting away heated fluid including a mixing and drying chamber and a discharge nozzle, a thick heat-insulating covering for the external surfaces of said apparatus, said apparatus having a fluid inlet passage therefor, positioned between the inner and outer surfaces of said insulating covering and substantially spaced from said surfaces.

12. I-Ieat-absorbing apparatus as set forth in claim 11, in which said fluid inlet passage provides a helical path for the fluid.

13. Apparatus for absorbing solar energy comprising a conical tube having an internal reecting surface, a transparent window through which solar heat rays are admitted to the larger end of said tube, a conduit through which a heat-absorbing uid is delivered to said tube through its larger open end, and means to conduct heated uid from the smaller end of said tube, said means for conducting away heated fluid including a mixing and drying chamber, and inlet and outlet connections to said chamber, which connections are positioned substantially out of alignment with each other.

14. Apparatus for absorbing solar energy comprising a conical tube having an internal reflecting surface, a transparent window through which solar heat rays are admitted to the larger end of said tube, a conduit through which a heat-absorbing fluid Vis delivered to said tube through its larger open end, means to conduct heated fluid from the smaller end of said tube, and a directing member mounted within said conical tube and spaced from the internal conical Wall thereof, said member directing fluid entering said tube outwardly toward said internal conical wall.

15. Apparatus for absorbing solar energy comprising a conical tube having an internal reiiecting surface, a transparent window through which solar heat rays are admitted to the larger end of said tube, a conduit through which a heat-absorbing fluid is delivered to said tube through its larger open end, means to conduct heated fluid from the smaller end of said tube, and a reversely tapered tubular conical member axially centered in spaced relation to the internal surface of said conical tube and outwardly deiiecting fluid entering said tube.

16. Heat-absorbing apparatus comprising a heating tube, means to direct solar heat rays into said tube, a mixing chamber, means to conduct heated vapor from said tube to said chamber, 

